My butt wound finally closed after three years and a second surgery. I still sit on a cushion though.... waiting until the scar tissue is very strong. When I don't sit on the cushion I do find it hurts some after a while. The cushion I got is from roho -- I take the cover off. It's expensive ($80), but I've had it for a year with daily use and no leaks. Highly recommended. here's the link: http://www.amazon.com/gp/product/B000OXDJ1U/ref=wms_ohs_product?ie=UTF8&psc=1
Honestly, it's not good for anyone to sit for a long period of time..... when I couldn't sit much I made a standing setup (just a stool on my desk for my computer with a separate keyboard lower) so I could work standing up for a while.... .at least at home, also helps a lot. The scar tissue is only 80% as strong as regular tissue, so there might be some limitation.
Veganostomy, what finally closed my wound was a new product called endoform, that I got from my nurse. It was incredible.... wound had been stuck for over a year, plastic surgeon wanted to do another surgery and start over, and then I saw improvement in one day (although it took several months to close all the way). Some chronic wounds get off balance, and the proteins that normally clean the wound also clean the collagens you need to close it.... the endoform is made from sheep gut and restores the balance (if that is the problem).
I don't work for either of these companies
.... just tried a lot of things....